Background and Objectives: Vaccination being the only way to reduce mortality from the dreaded COVID-19 disease, the vaccine was introduced in India as per the advice of the National Expert Group on January 16, 2021.Duration of immune response elicited by the vaccines has always been a matter of content.With new variants emerging every other day, the study was done to look for the antibody response in vaccine recipients post second dose of vaccination.Materials and Methods: A longitudinal observational study was conducted from August 2021 to shoe palace proofer February 2022 in fully vaccinated individuals who took either Covishield (AZD1222) or Covaxin (BBV-152).
Blood was collected from the individuals at 12-16 weeks post-vaccination to look for IgG antibody response against S1 spike protein of SARS-CoV2 by ELISA.Follow-up was done at 32 weeks post the second dose in individuals who had received Covishield.Results: Among 176 individuals, IgG antibody against S1 spike protein was found to be positive in abc always be coding 89.7% (158).
Covishield recipients showed higher antibody response (99.1%) as compared to Covaxin recipients (71%).Antibody response was higher in males, individuals less than 50 years, and non-comorbid individuals.Of 38 Covishield recipients, IgG antibody response was positive in 28 (73.
6%) individuals when followed up at 32 weeks post the second vaccination dose.Conclusion: The study gives us input with regard to the long-term antibody kinetics of both vaccines.The study has a follow-up plan to co-relate the antibody response to the neutralization test.